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A 3 Phase, 10 KVA load has power factor of 0.342. The power is measured by two wattmeter method. Find reading of each wattmeter when i) Power Factor is leading ii) Power Factor is logging
1 Answer
written 7.8 years ago by |
Given
$10\times10^3 VA \\ Pf=0.342 \\ P_{apperent}=10kvk \\ \sqrt3V_LI_L=10^4 \\ V_LI_L=\dfrac{10^4}{\sqrt3}=5773.5VA \\ pf=0.342 \emptyset=\cos_{-1}(0.342)$
1. Pf is lending, then
$\hspace{0.5cm}$ $w_1=V_LI_L \cos(30-\emptyset)=5773 \cos(30-70) \\=4422.76watt \\=4.42kw \\ w_2=V_LI_L \cos(30+\emptyset)=-1002.55watt \\ =-1.0025kw$
2. pf is logging, then
$\hspace{0.5cm}$ $w_1=V_LI_L \cos(30+\emptyset)=5773\cos(30+70) \\ =-1.0025kw \\w_2=V_LI_L\cos(30-\emptyset)=4.42kw$